package utils;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.net.URLEncoder;
import java.text.SimpleDateFormat;
import java.util.*;

public class POIUtils {
    private final static String xls = "xls";
    private final static String xlsx = "xlsx";
    private final static String DATE_FORMAT = "yyyy/MM/dd";
    /**
     * 读入excel文件，解析后返回
     * @param file
     * @throws IOException
     */
    public static List<String[]> readExcel(MultipartFile file) throws IOException {
        //检查文件
        checkFile(file);
        //获得Workbook工作薄对象
        Workbook workbook = getWorkBook(file);
        //创建返回对象，把每行中的值作为一个数组，所有行作为一个集合返回
        List<String[]> list = new ArrayList<String[]>();
        if(workbook != null){
            for(int sheetNum = 0;sheetNum < workbook.getNumberOfSheets();sheetNum++){
                //获得当前sheet工作表
                Sheet sheet = workbook.getSheetAt(sheetNum);
                if(sheet == null){
                    continue;
                }
                //获得当前sheet的开始行
                int firstRowNum  = sheet.getFirstRowNum();
                //获得当前sheet的结束行
                int lastRowNum = sheet.getLastRowNum();
                //循环除了第一行的所有行
                for(int rowNum = firstRowNum+1;rowNum <= lastRowNum;rowNum++){
                    //获得当前行
                    Row row = sheet.getRow(rowNum);
                    if(row == null){
                        continue;
                    }
                    //获得当前行的开始列
                    int firstCellNum = row.getFirstCellNum();
                    //获得当前行的列数
                    int lastCellNum = row.getPhysicalNumberOfCells();
                    String[] cells = new String[row.getPhysicalNumberOfCells()];
                    //循环当前行
                    for(int cellNum = firstCellNum; cellNum < lastCellNum;cellNum++){
                        Cell cell = row.getCell(cellNum);
                        cells[cellNum] = getCellValue(cell);
                    }
                    list.add(cells);
                }
            }
            workbook.close();
        }
        return list;
    }

    //校验文件是否合法
    public static void checkFile(MultipartFile file) throws IOException{
        //判断文件是否存在
        if(null == file){
            throw new FileNotFoundException("文件不存在！");
        }
        //获得文件名
        String fileName = file.getOriginalFilename();
        //判断文件是否是excel文件
        if(!fileName.endsWith(xls) && !fileName.endsWith(xlsx)){
            throw new IOException(fileName + "不是excel文件");
        }
    }
    public static Workbook getWorkBook(MultipartFile file) {
        //获得文件名
        String fileName = file.getOriginalFilename();
        //创建Workbook工作薄对象，表示整个excel
        Workbook workbook = null;
        try {
            //获取excel文件的io流
            InputStream is = file.getInputStream();
            //根据文件后缀名不同(xls和xlsx)获得不同的Workbook实现类对象
            if(fileName.endsWith(xls)){
                //2003
                workbook = new HSSFWorkbook(is);
            }else if(fileName.endsWith(xlsx)){
                //2007
                workbook = new XSSFWorkbook(is);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return workbook;
    }
    public static String getCellValue(Cell cell){
        String cellValue = "";
        if(cell == null){
            return cellValue;
        }
        //如果当前单元格内容为日期类型，需要特殊处理
        String dataFormatString = cell.getCellStyle().getDataFormatString();
        if(dataFormatString.equals("m/d/yy")){
            cellValue = new SimpleDateFormat(DATE_FORMAT).format(cell.getDateCellValue());
            return cellValue;
        }
        //把数字当成String来读，避免出现1读成1.0的情况
        if(cell.getCellType() == Cell.CELL_TYPE_NUMERIC){
            cell.setCellType(Cell.CELL_TYPE_STRING);
        }
        //判断数据的类型
        switch (cell.getCellType()){
            case Cell.CELL_TYPE_NUMERIC: //数字
                cellValue = String.valueOf(cell.getNumericCellValue());
                break;
            case Cell.CELL_TYPE_STRING: //字符串
                cellValue = String.valueOf(cell.getStringCellValue());
                break;
            case Cell.CELL_TYPE_BOOLEAN: //Boolean
                cellValue = String.valueOf(cell.getBooleanCellValue());
                break;
            case Cell.CELL_TYPE_FORMULA: //公式
                cellValue = String.valueOf(cell.getCellFormula());
                break;
            case Cell.CELL_TYPE_BLANK: //空值
                cellValue = "";
                break;
            case Cell.CELL_TYPE_ERROR: //故障
                cellValue = "非法字符";
                break;
            default:
                cellValue = "未知类型";
                break;
        }
        return cellValue;
    }

    //导出
    public static void exportExcelUtil(String[] header, List<LinkedHashMap<String, Object>> dataListMap, HttpServletResponse response){
        //查询所有记录
        //2、创建一个XSSFWorkbook，对应一个Excel文件
        XSSFWorkbook workbook = new XSSFWorkbook();
        try{
            // 4、在workbook中添加一个sheet,对应Excel文件中的sheet
            XSSFSheet sheet = workbook.createSheet();
            // 声明列对象
            XSSFCell cell;
            // 5. 标题写入第一行数据，第0行,
            XSSFRow row = sheet.createRow(0);
            for (int i = 0; i < header.length; i++) {
                //在第一行创建第i格单元格
                cell = row.createCell(i);
                cell.setCellValue(header[i]);
            }
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
            // 6. 循环写入列表数据
            //将数据循环放入excel
            for (int i = 0; i < dataListMap.size(); i++) {
                //获取list集合中的每一个对象
                Map<String,Object> map = dataListMap.get(i);
                //将对象依次放入excel中
                Row dataRow = sheet.createRow(i + 1);
                int cellIndex=0;
                for (String key : map.keySet()) {
                    //如果是date类型
                    if (map.get(key) instanceof Date){
                        dataRow.createCell(cellIndex++).setCellValue(sdf.format(map.get(key)));
                    }else if (key.equals("sex")){
                        if (map.get(key).toString().equals("1")){
                            dataRow.createCell(cellIndex++).setCellValue("男");
                        }else{
                            dataRow.createCell(cellIndex++).setCellValue("女");
                        }
                    }/*
                          Room room=  roomService.name(strings[5]);
                     if (room.getId()==null){
                         Room room1 = new Room();
                         room1.setName(strings[5]);
                     int rid=    roomService.add(room1);
                     stu.setRid(rid);
                     }else {
                         stu.setRid(room.getId());
                     }
                    else if (key.equals("workstate")){
                        if (map.get(key).toString().equals("1")){
                            dataRow.createCell(cellIndex++).setCellValue("上班");
                        }else{
                            dataRow.createCell(cellIndex++).setCellValue("休假");
                        }
                    }*/
                    else{
                        dataRow.createCell(cellIndex++).setCellValue(map.get(key).toString());
                    }
                }
            }
            // 7. 将Workbook写入文件

            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode("校区列表.xlsx", "UTF-8"));
            response.setHeader("Connection", "close");
            response.setHeader("Content-Type", "application/octet-stream");
            workbook.write(response.getOutputStream());
        } catch (Exception e) {
        }
    }





}
